This is javascript toaster library integrated along with Laravel You need to add this file within config/app.php like as
'Toaster' => App\Utils\Toaster::class,
after that you simply can use it within your project using like as
use App\Utils\Toaster;
within file you simply use
Toaster::error("Your failure message.")->error('Another message');
instead of
withFlashDanger / withFlashSuccess
And you need to place following code within your main blade file like as
{!! Toaster::renderToasters() !!}